I have also an album called Quantum Tunnel, with songs inspired by Portal and remixes from Portal, and all that on Bandcamp:
http://luigiblood.bandcamp.comBuy it, or just download it for free, I don't mind. ^^
The cover art is made by Tomycase which I really suggest to take a look at what he does, and he's really nice too. (I'd love to work on a Portal 2 mod with those songs)

It's supposed to be a chasing song for a level of the game, which I will not talk about since it spoils the story and it means a lot here.
I also made this song for messing with the plugins I got today.